Herman M V, Ingram D A, Levy J A, Cook J R, Athans R J
Department of Medicine, New York Medical College, Valhalla.
Clin Cardiol. 1991 Jun;14(6):469-76.
Variability in precordial lead placement is a recognized source of electrocardiographic inaccuracy and lack of reproducibility. In an attempt to reduce error, we evaluated a new device to facilitate and guide precordial lead placement. This study involved three phases: (1) comparison of device-guided electrocardiogram with ECGs obtained by deliberate misplacement of precordial leads on the same patient; (2) electrocardiograms obtained by using the precordial lead device versus those obtained by standard technician methods; (3) reproducibility of precordial electrocardiographic leads between two technicians using the device to guide lead placement. Deliberate misplacement of precordial leads by 2 cm resulted in significant electrocardiographic interpretation changes in all patients. Comparing electrocardiograms obtained after device-guided precordial placement with those obtained after technician placement resulted in variations in 60% of patients including changes in R-wave amplitude, ST segments, Q waves, and transition zone. Significant Q-wave appearance/disappearance and/or significant ST-segment elevation/depression occurred in 19% of patients in Phase II. Sixteen percent of electrocardiograms showed significant changes when analyzed by an experienced electrocardiographer and 10% when interpreted by computer. Variable lead placements and resulting electrocardiographic alterations were not seen by either of two technicians when the device was used. This study confirms the widespread variability in precordial electrocardiograms secondary to lead misplacement. The use of a device to assist in the placement of precordial leads ensures accuracy and reproducibility of electrocardiography. Improved precision and quality control in this laboratory test have important implications in health care and its costs.
心前区导联放置的变异性是公认的心电图不准确和缺乏可重复性的原因。为了减少误差，我们评估了一种有助于并指导心前区导联放置的新设备。本研究包括三个阶段：（1）将设备引导的心电图与同一患者心前区导联故意放置错误时获得的心电图进行比较；（2）使用心前区导联设备获得的心电图与标准技术人员方法获得的心电图进行比较；（3）两名技术人员使用该设备引导导联放置时心前区心电图导联的可重复性。心前区导联故意错位2厘米导致所有患者的心电图解读发生显著变化。将设备引导的心前区放置后获得的心电图与技术人员放置后获得的心电图进行比较，60%的患者出现了变化，包括R波振幅、ST段、Q波和过渡区的变化。在第二阶段，19%的患者出现了显著的Q波出现/消失和/或显著的ST段抬高/压低。由经验丰富的心电图专家分析时，16%的心电图显示有显著变化，由计算机解读时为10%。当使用该设备时，两名技术人员均未发现导联放置的变化以及由此导致的心电图改变。本研究证实了由于导联放置错误导致的心前区心电图广泛存在变异性。使用一种设备辅助心前区导联的放置可确保心电图的准确性和可重复性。在这项实验室检查中提高精度和质量控制对医疗保健及其成本具有重要意义。
